Genetic testing—either to diagnose a condition or predict its chance of occurring in the future—has become more widespread in medical practice. Rapid advances in technology mean that quick and affordable results can be obtained in an increasing range of situations which can help the clinician determine, for example, treatments, surveillance or preventive options. Whether and when such tests should be done before the potential onset of a condition, and in those too young to yet decide for themselves whether they want this information, remains a debated issue.

On the one hand, parents have a legitimate interest in discovering what the future might hold for their children. Helping children and their parents to come to terms with a likely genetic condition in the future at an early stage and gear their lives accordingly could be seen as an argument in favour of testing. On the other, if that future will not be realised until the children have grown into adults, then why not wait until the children are old enough to decide for themselves whether or not they want to know this information? Providing parents with a crystal ball about their children as adults may not be something that health professionals see as their role, or indeed be thanked for providing by the children as they grow older. Parental requests for such …